City G and City H is 240 km apart. Albert left City G for City H at 10.00 a.m. travelling at an average speed of 60 km/h. Ian left City G later than Albert and caught up with him at 12.00 p.m. Ian was travelling at a speed of 72 km/h.
- At what time did Ian leave City G?
- How much later did Albert arrive in City H than Ian? Express your answer in h as a fraction or mixed number.
(a)
From 10.00 a.m. to 12.00 p.m. = 2 h
Distance that Albert covered when Ian caught up with Albert
= 2 x 60
= 120 km
Time that Ian took to travel 120 km
= 120 ÷ 72
= 1
23 h
1 h = 60 min
23 h =
23 x 60 = 40 min
1
23 h = 1 h 40 min
Time that Ian left City G:
1 h 40 min before 12.00 p.m. = 10.20 a.m.
(b)
Remaining distance that they had to cover to reach City H
= 240 - 120
= 120 km
Duration that Ian had to travel before reaching City H
= 120 ÷ 72
= 1
23 h
Duration that Albert had to travel before reaching City H
= 120 ÷ 60
= 2 h
Duration that Albert took to arrive later than Ian in City H
= 2 - 1
23=
13 h
Answer(s): (a) 10.20 a.m.; (b)
13 h
